A concrete-distribution rig of this type is known (DE-PS 34 46 290), wherein all rig arms 1, 2, 3, 4 and 5 can be folded against one another at their hinged joints B, C, D and E like a multi-Z-folding. This concrete-distribution rig reaches very far and can be advantageously utilized both in the low-rise building construction and also in the high-rise building construction. The multi-Z-folding further guarantees a quick operational readiness after only a short lifting and partial unfolding of the arm package. The rig also provides a high flexibility, in particular, during the pouring of concrete or the concreting of difficult to access areas whereby dead spaces are essentially avoided during upward feed near the vehicle and also during the pouring of concrete in low spaces. In order to also achieve a mass distribution favorable for the load and moment to be absorbed by the chassis when in the folded travelling position, the hinged joints C and E near the front axle have a swivelling range of 270.degree. between the arms 2 and 3 or 4 and 5, whereas the remaining hinged joints B and D have an angle of traverse of 180.degree.. The pouring of concrete parallel to or along the working plane is possible with the multi-Z-folding. However, to guide the end hose all the way to the cab requires a relatively high unfolding height.
Furthermore, in a concrete-distribution rig with four rig arms, it is actually known to fold the rig arms 1, 2 and 3 against one another at their hinged joints B and C in opposite rotational directions like a Z and to fold the rig arm 4 at the joint D in the same rotational direction with the rig arms 2 and 3 against one another. This type of folding has been specially designed for pouring concrete in low spaces because the end hose can be moved over the entire work area from the cab to the maximum extension with a small unfolding height along a predetermined horizontal operating line. However, this four-arm distribution rig cannot be used to provide parallel hose guiding when concrete is supposed to be poured beyond obstacles or from the ground into higher stories.